The present invention relates to a particle analyzer and a particle analysis method and, more particularly, to the analysis of cells and other formed components contained in blood or urine.
Chemiluminescence detection apparatuses have been described, wherein a photodetector detects the intensity of chemiluminescence occurring in a reaction cell. The apparatus is characterized in that a temperature sensor is provided in the vicinity of the reaction cell, and the intensity of chemiluminescence is thereby corrected on the basis of the temperature obtained by the temperature sensor (for example, Japanese Unexamined Patent Publication No. H6-201585).
Another example is an automatic analysis apparatus for detecting a chemical reaction by using a final reaction detection reagent such as a luminescent reagent. The apparatus includes a temperature measuring means for measuring the temperature of the final reaction detection reagent solution and a correcting means for correcting a final detection value on the basis of the measured temperature of the final reaction detection reagent solution (for example, Japanese Unexamined Patent Publication No. 2001-74749).
An example of a particle analyzer for analyzing particles, such as cells and blood cells in a sample liquid, is a flow cytometer using a sheath flow scheme. According to this scheme, sheath liquid flows around a particles-containing liquid ejected from a nozzle, and thereby forms sample liquid. In this scheme, the flow of the particles-containing liquid is narrowed hydrodynamically in the sheath flow cell. An optical measurement is performed at this site, whereby the particles in the particles-containing liquid are measured and analyzed.
The term “sheath flow” indicates a flow (e.g., of sample liquid) in which particles-containing liquid is narrowed substantially to the diameter of a particle, in the center part of sheath liquid flowing through an orifice in a laminar flow state, in which the particles accordingly pass through the orifice aligned in one line. Sample liquid prepared from a sample such as blood with a stain liquid, a hemolyzing agent, a reaction reagent, or the like is introduced into a flow cytometer, whereby various cells are analyzed.
In the above-mentioned optical measurement, the sample liquid is irradiated with light, whereby light generated from the particles in the sample liquid by the irradiated light is received by a photo-detector, and thereby converted into an electric signal. The electric signal is amplified by an amplifying section, and then the particles are analyzed on the basis of the electric signal.
Nevertheless, when the temperature of the sample liquid changes, the intensity of light from the particles also changes. This adversely affects the analysis result. Thus, a problem has resulted in that the sample liquid needs to be managed strictly at a predetermined temperature by using a incubator or the like.